In the liver, glucose is converted to glucuronic acid and ascorbic acid (except in human beings and other species in which ascorbate and pentose are produced) through uronic acid pathway. It is also considered as an alternative pathway that does not lead to the formation of ATP. Glucose 6-phosphate reacts with uridine triose phosphate to form uridine diphosphate glucose (UDPGlc) in a reaction catalysed by UDPGlc pyrophosphorylase, as in glycogen synthesis. UDP-glucuronate occurs in a two-step reaction catalysed by UDPGlc dehydrogenase.

UDP-glucuronate is the precursor for glucuronate and is involved in its incorporation into proteoglycans or for synthesis of substrates such as steroid hormones, and a number of drugs that are excreted in urine or bile as UDP-glucuronide conjugates.